


i loved you first (and the history books forgot about us)

by reyesoflight, spadeflake



Category: The 100 (TV)
Genre: Alternate Universe - Merpeople, Angst with a Happy Ending, F/F, Lostia
Language: English
Status: In-Progress
Published: 2017-05-09
Updated: 2017-05-09
Packaged: 2018-10-29 21:42:38
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 3,128
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10862658
Author URL: https://archiveofourown.org/users/reyesoflight/pseuds/reyesoflight, https://archiveofourown.org/users/spadeflake/pseuds/spadeflake
Summary: Merpeople AU: "Kom woda 'so gyon op, gon woda 'so kom daun. // From water we are born, to water we return."





	i loved you first (and the history books forgot about us)

**Author's Note:**

> The product of [Blake](http://archiveofourown.org/users/spadeflake) nerding out about mermaids from around 6am-8am to [Kay](http://archiveofourown.org/users/reyesoflight) (6pm-8pm) and getting zero sleep because Blake is a bad human being.  
> And we noticed how much Costia is slept on so we had to fix that.

Light pours in from wide open windows and heat the tiles beneath Costia’s feet. She watches as the rays dance across Lexa’s face, highlighting her expressions that intensify the words leaving her mouth. Brown hair slips from brown skin as she begins to talk with her hands. And Costia is in love.

“Be kind to your brothers and sisters and all who you consider your allies else your heart will rot. For that, there is no cure. A rotten heart will spread to the furthest reaches of your fingertips and leave nothing for your next life to take with it. And you will stay in darkness forever,” she says, tone low and grave, as if she’s sharing a secret. The Nightbloods have their eyes glued to Lexa. Their bodies tense with restless energy and angle as close to her as possible, absorbing every sound that’s released from their Heda’s lips.

“Stay kind or monsters will come for you in humanlike form, drag you from your beds beneath the moon’s light, and drown you in your sleep. And you will awake to the feeling of your lungs crushing only to find the end,” she continues. If the Nightbloods are afraid, they don’t show it, as they are trained.

“Heda,” Costia calls out softly, gaining Lexa’s attention. The sun catches in her green eyes and she is beautiful. “May I have a word?” she asks, smiling warmly.

“Of course, Costia,” Lexa replies, a slight tremor in her voice. She stands and the children scramble to leave, heading outside to continue their sparring session with Titus’ supervision. Lexa watches them with thinly veiled affection and Costia feels a wave of love for her girlfriend.

“You’re scaring them,” she chides fondly.

“They’re Nightblood. They can handle a little story,” Lexa says, taking Costia’s hands into her own. “Don’t worry.”

“If the Floukru elders heard you say that about their beloved merpeople lore, you’d get in trouble,” Costia scolds, light heart betraying her breath.

“Well then, how can I convince you to keep this between us?” she asks, pulling her lover closer.

“I wonder,” Costia responds, softly caressing Lexa’s palms. She pouts her lips and feigns heavy thought before breaking into a giggle when Lexa’s hands reach up to cup her cheeks. “This is inappropriate, Heda.”

“No one’s around to notice,” she whispers, coaxing Costia into a tender kiss.

A cough sounds from behind them, causing them to separate. Lexa’s annoyance is immediately made visible on her features while Costia attempts to hide her amusement.

“Isn’t it a little early in the morning for this?” It’s Anya and the teasing tone of her voice drags out a laugh from the both of them.

“Luna called for you,” she says flatly to Lexa who nods in understanding. This would determine their next move against the Azgeda.

“It seems I have business to attend to so we’ll have to postpone your bribery. I’ll see you soon,” Lexa promises, cheek pressed to Costia’s as she’s enclosed in arms that feel like home. She melts, allowing herself another moment, before the gravity of her title falls firmly on her shoulders and she takes her leave.

“She loves you,” Anya says, turning to Costia. “I’ve known her for all her life and I’ve never seen her care so deeply before and with all of her being. Frankly, it’s disgusting, troublesome, and stupid. But she isn’t so boring when her personality is made up of more than just Heda and pupil. So don’t fuck it up.”

“I won’t,” Costia swears and she can see in Anya’s eyes that she believes her.

She loves Lexa more than anything and this promise is one she intents to keep till her last breath. The world they live in is full of uncertainty. That’s what it means to live and even more to love. And yet, Costia’s never been more sure of anything than her feelings for Lexa and their love for each other.

That conversation is what pushes Costia to finally craft Lexa a sonraun. The  _ sonraun _ is a charm that holds one’s soul. It symbolizes the promise of eternity and the Floukru, Costia’s people, believe that whoever you gift your own, you’ll be reunited with in every life. Passing one to your most beloved is a tradition more sacred than marriage and Costia hopes Lexa will accept it. Though Lexa is of the Trikru, she cherishes Costia’s beliefs on par with her own. When she receives this, Costia’s innermost truth will lay bare in Lexa’s palm and she will know it.

She takes a pen and wills herself to convey the depth of her love on paper, but the words don’t flow out easily. Costia’s afraid she won’t be able to express what she truly means. She starts off with a sentence proclaiming her feelings boldly atop the page, but crumples it up, deciding it doesn’t rightly portray her emotions. So she locks herself away in her tent for hours, trying over and over again to come up with anything that feels enough. Then she realizes she will never be fully satisfied with simple text so she paints a memory with them instead.

Before she can finish, she hears shouting from a general. The sound of feet scrambling to position is deafening and she hurries to join, leaving the sonraun and incomplete letter behind. They call for defense against the Azgeda’s attack. There’s no time to think. She quickly gathers up her supplies and runs to the battlefield, her eyes searching for any wounded warriors.

Her job is messy and, more often than not, the fight ends with too much blood on her hands. Too many people whose lives she could not save even when she’d tried her hardest; pushed her draining emotions on the back burner and listened to her lessons on repeat in her head. It puts a heavy weight on her. The thought of returning home into Lexa’s arms is what usually sates her, but today, there’s an unusual amount of tensity in the air and she worries of what that might bring. Again, Costia pushes that aside and focuses on bringing back more bodies, dead or alive, to the healers’ tent.

She’s just running out for another when she feels something looming behind her a second before a flash of white. Blackness falls over her eyes. She sees the ground moving beneath her feet under a veil of dirty cloth and feels the rough material shift over her temples with periodic lapses in consciousness. The pain radiating from the base of her skull dims the terrain’s abuse of her limp body. She hears the roars of battle through cotton drifting farther away. And a current of defiance courses through her. Costia kicks herself up and fights against arms that burn like fire. She reaches out to where Lexa must be with all her might and cries out in a desperate attempt for rescue. It goes unheard. Another hit to the head and darkness imprisons her once again.

The first thing she hears are the repeated drips of water from the ceiling to the slick stone ground below. They grow in volume as she tries to force herself awake. It’s maddening. Her head lulls to the side and she remembers. Suddenly, her eyes are wide and she thrusts herself forward only to fall back to the wooden seat she’s strapped to. Still, she struggles against her restraints. Looking up, she sees a man, back to her, placing down differently shaped blades side by side.

“Let me go,” Costia demands, fear thick in her throat and hair standing on end.

Her plea goes ignored, only answered by the sounds of metal scraping against metal, adding to her current mental hysteria.

“Let me go,” she tries again, raising her voice. She shakes her head to herself in disbelief. “It can’t end like this. It won’t. I won’t let it.”

Footsteps echo wall to wall, amplifying the pounding inside Costia’s chest. Nia, queen of the Azgeda, steps into view shortly after. This woman standing before her with that idiotic grin on her face confirms that what she was most afraid of is the reality. All she can do in this moment is pray that she’ll get lucky and be able to cut that cocky expression right from Nia’s face.

“Costia of the Floukru, I’m so glad we finally meet,” Nia greets casually. She dismisses the meat who dragged Costia here and makes her way to the tools he obediently laid out. “How unfortunate that it isn’t under better circumstances.”

Costia lets out a bitter laugh. “This played out exactly how you wanted. You’ve always had a flare for dramatics,” she says, watching the way Nia cradles a knife in her hands. She shivers, hair standing on end.

“It seems unfair that you already know so much of me and yet, all I know of you is that you belong to the Heda. We should remedy that.”

“And that’s what this is about, isn’t it? Your war with Lexa. You wish to hurt her and this is the only way you can,” Costia bites. “You’re weak.”

Nia allows the room to grow deadly quiet before taking the knife to her jugular, dragging lightly so that only a single drop of blood escapes. Sweat forms on Costia’s rich umber skin as she feels her throat pulse against the blade, pushing it deeper. She doesn’t so much as flinch. Internally, she screams. Not in pain, but in knowing. Knowing that she may never see another sunrise with her beloved; may never again share the same breath, the same touch. And she is angry, furious with herself, for not loving her more wholly and fiercely when she had the chance. She prays that if this is how she’s stripped of life, her sounran will make it into her beloved’s possessions so that they may meet again, even if not in this time.

“Have you nothing more to say?” Nia asks, eyes frigid. She smirks and Costia almost feels sorry for her. This is where she’s happiest. A place where others rest below her feet. Alone.

Costia holds her tongue.

“That won’t work for me.” And suddenly, the knife is driven through her hand and latched to the wooden plane beneath. Pain shoots through Costia’s being. She impulsively attempts to fist her hand and pull away, but she’s stuck and her suffering only worsens.

“See, there’s something I want from you and you’re going to give it to me.” Nia turns and picks up another knife, one with a jagged ridge and curved tip.

“Where is Lexa’s tent? Who guards it?” she asks, trailing it under Costia’s cheek.

“How many strong is her army?” she continues, taking the weapon down to Costia’s uninjured hand. She flinches involuntarily as Nia wedges it under her nail.

“What’s her battle plan?” Nia rubs the sensitive skin there back and forth, baiting a pained whimper from Costia’s throat. But she refuses to speak, her mouth locked shut.

“Tell me,” she commands, haphazardly yanking the nail off. Costia’s only reaction is to clamp down harder, drawing focus to her lips being torn apart by her own teeth. So Nia works left to right until there’s not a nail left attached to Cosia’s body before taking up a rag and bucket of water and dropping it at Costia’s feet.

“I do regret that we met under these circumstances. You could have been an acceptable asset,” Nia confesses, humor audible.

“Lexa will come and you’ll feel that regret in the very core of your heart before it’s ripped out,” Costia spits, adrenaline provoking her recklessness.

“Don’t hold out too much hope.” Nia’s blue eyes glint and her voice drips venom. “The Heda has other things to worry about.”

Costia swallows her fear, evading the part of her that thinks Lexa will not come. Somewhat out of spite and somewhat because she has to. She has to believe in Lexa. The hope that she’ll see her, just once more, is the only thing that could possibly get her through whatever hell the Azgeda have planned for her. And the only thing that’ll keep her sane.

“She will come for me,” Costia insists, ignoring the twisting anguish she feels and looking right into Nia’s cold, calculative eyes. She refuses to show any sign of doubt. She refuses to back down.

Nia steps behind her, her fingertips dragging across Costia’s bare ashen shoulder. It sends a chill running down her spine. “It’s very naive of you to think that Lexa will come for you.” Nia releases a heartless laugh. “Use your brain. We know that she’s your beloved, don’t you think they do too?”

“That doesn’t matter,” Costia mutters, raw voice sounding strange in her own ears.

“But it does,” Nia taunts. “The Heda isn’t allowed to have such distraction. What makes you think the council will allow her to come after you?”

Costia hopes the twitch of her black eyes don’t portray the wave of dread that courses through her veins. Nia’s words burn in her mind, though a small part of her had known it would end this way as soon as she had awakened, away from the battlefield and in the cold, dreary darkness of the Azgeda’s dungeon.

Ultimately, she accepts it. She’s lived a good life. One filled with the kind of happiness and love that only a soulmate could provide. So if this is how she goes, so be it. She’ll be at peace knowing she just made it. As long as Lexa finds her sonraun. As long as they still have a chance. A chance to find each other once more.

Her silence spurs Nia on. “What makes you think they’re willing to risk even a handful of lives over you? You’ll just be another casualty of this war. No one else will remember you. It may hurt Lexa for as long as I need it too, but eventually, she’ll move on too. And you’ll be left behind, rotting under the sea,” she sneers.

“You’re wrong.” Costia admits to herself that she sounds tired, weak, but she needs to fight and so she does. Verbally with Nia and mentally with herself.

“Aren’t you angry? That after everything you’ve given, this is how you’re repaid. Why stay loyal to those cowards? Give me the power to act as your revenge.” She grips both of Costia’s shoulders tightly, holding her strong gaze, searching.

“No.”

Nia’s eyes cloud over and she picks up the rag. She forcibly pulls Costia’s head back and ties it down before setting the rag over her face, covering her eyes, nose, and mouth.

“I promise this to you, Costia of the Floukru. I won’t be the one made to feel regret.”

She takes the bucket over her head and pours a slow, steady stream. Costia feels her lungs constrict. It hurts. Of course, it hurts. She feels as though she's drowning. How ironic for one of the Floukru. Torture by water. If she wasn't fighting for breath, she'd probably laugh. Struggling only makes it worse. So she tries to calm herself. Relax. Let it happen. Easier thought than done. So she thinks of Lexa while her lungs burn and body convulses. How they first met plays out rapidly for her behind her closed lids. At the end, she sees white. The rag is lifted off her mouth and she coughs up water. Oh, how it stings.

"Talk," Nia demands.

Costia is still gasping for breath, eyes shut to keep her blurred vision at bay, when Nia grabs her by the throat, clenching it between her pale, bony fingers. If the reaper came in human form, she's sure they would take the appearance of the crazy white woman causing her this misery.

"Talk."

Her voice seems considerably quieter than before. She says more, but Costia's ears can’t pick it up. Her eyes grow heavy. She's tired; so very tired. Then, she’s nothing.

The coming weeks play out the same as the first day. Costia remains stubborn, but she’s losing will by the hour. It’s been fifteen days. Costia solely reserves her energy for longing thoughts of Lexa. Not of regret, but more promises. She’s sure that she’ll complete them next time. She’s stopped hoping for rescue long ago. Every wish made instead is to somehow be reunited with her beloved. Before or after she’s gone. It’s all the same. Maybe it’s selfish to want to chain Lexa to herself, but oh, how she wants. It doesn’t feel wrong.

Nia’s made it clear that she no longer has a use for her. So here Costia kneels, blindfolded and chained. Too weak to fight. Her senses so dim that all she can hear is the slow and calm beating of her own heart. She feels someone behind her and knows Nia’s made a spectacle of it. Her last moments. And she can’t bring herself to be angry or hurt or anything at all that isn’t loving and longing for Lexa.

She prays that when they do meet again, they’ll do all the little things that they never got the chance to do in this life. Maybe then, neither of them would have to carry the weight of the world on their shoulders. They could just be Lexa and Costia, or whatever names they may have. Two girls who love each other so strongly and simply that nothing could stand in their way. Not this time. There’d be no promises tying either of them to anything, anyone, but each other.

Costia always wondered what it would be like for them to get married and build up a little family of their own. She’s seen how kind and patient Lexa is with the Nightbloods, always looking after them and ensuring that they’re safe, sound, and strong. Lexa loves them like they’re her own and Costia thinks of how wonderful it’d be to have that with Lexa and a kid of their own. They’d never be able to in this life, even if Costia weren’t about to face her death so soon. Lexa is the Heda and that had always made such a life an impossibility. Just being with Costia already made it hard enough on her and sometimes Costia would entertain thoughts of how things might be better off for Lexa without her. But she knows and trusts with all of her being that Lexa loves her too and she wouldn’t trade that love for anything in this world. Unfortunately, this world is fading fast. So she prays once more. For next time.

The last thing she feels while she’s here is the thick, rusted blade hacking at the back of her neck. The last thing she feels while she’s not is Lexa.

**Author's Note:**

> Find us on tumblr at [reyesoflight](mcggiesawyr.tumblr.com) and [spadeflake](blakebat.tumblr.com).


End file.
